In the case of paste-like toothpaste used most frequently among all types of toothpastes, it has high dispersion stability and is favorable to formulation of various pharmaceutically effective ingredients. In addition, it has high shape retentivity and is favorable to maintenance of its shape after disposing toothpaste from the container thereof. However, such paste-like toothpaste has insufficient flowability due to high viscosity or the like, requires a large extent of force during its ejection from a tube to show inconvenience of use, and has low releasability to show a bad feeling of use.
Meanwhile, in the case of the conventional liquid toothpaste, it has excellent releasability but shows poor dispersion stability, and thus is limited in formulation of pharmaceutically effective ingredients. Moreover, in the case of such conventional liquid toothpaste, phase separation occurs during its distribution or use, resulting in loss of commodity value. In addition, it has insufficient shape retentivity, cannot retain a predetermined shape after disposing toothpaste onto a toothbrush, and infiltrates to the gap in the toothbrush, resulting in inconvenience of use.
Korean Patent Application No. 2001-7004081 discloses a liquid tooth washing gel having a controlled ratio of water to a wetting agent. However, the liquid tooth washing gel has problems related with shape retentivity and flowability. In addition, Korean Patent Application No. 2002-0053430 discloses improvement of shape retentivity and flowability using sodium caseinate, but the degree of improvement is insufficient to provide convenience of use to the users and sodium caseinate causes degradation of quality in terms of sensibility. Moreover, in the case of the conventional high-viscosity paste type toothpaste or liquid toothpaste, it is impossible to apply such toothpastes to various types of containers. In the case of the high-viscosity paste type toothpaste, it is difficult to eject the toothpaste when using a dip tube type pump and the toothpaste undergoes an increase in viscosity more with the lapse of time, leading to a failure in ejection. In the case of the conventional liquid toothpaste, it is not possible for the toothpaste to retain its shape even if it is ejected, leading to a failure in use.
The paste-like toothpaste that was developed first by Colgate Co. (USA) is sold in the form of an aluminum tube containing it. Even in 1970s′, such an aluminum tube was still used. Improvement from such a container for paste-like toothpaste to a currently used container made of an aluminum laminate film is made by the development of polymer and polymer processing technology. However, in the case of such a tube type toothpaste, there is a lot of inconvenience of use actually due to the residual amount upon the ejection from a tube and high viscosity of a paste-like product. Then, in order to enhance convenience of use, there has been an attempt to use a vacuum pump type plastic container so that highly viscous paste may be ejected from the container. A part of such products are on sale, but they have problems in terms of cost efficiency and low releasability of the conventional paste-like toothpaste.
In general, sorbitol has been used as a wetting agent and moisturizer for paste formulations.
In the case of sorbitol, it is used in the form of 70% solution. However, such solution may be transformed into a solid undesirably after water is dried. For this reason, there has been an attempt to provide the users with enhanced convenience of use by using a dispenser pump (dip pump) applied to shampoo or body wash. However, in the case of a dispenser pump, the internal contents may be dried due to free communication with the external air when viewed from the characteristics of the container, thereby causing an increase in viscosity and a failure in ejection. The internal contents may be even solidified, and thus commercialization is limited severely.
Additionally, in the case of a toothpaste formulation, the polishing agent contained in the toothpaste has a Mohs hardness of about 3-6, which is higher than the hardness of low density polyethylene forming the piston of a dispenser pump. Therefore, there is a problem in that the piston is worn by the polishing agent contained in the toothpaste, thereby making it difficult to eject the toothpaste. For this reason, there has been a need for preparing a toothpaste composition that provides high convenience of use like shampoo and body wash by using a dispenser pump, and can be used without malfunction of a pump caused by wearing of a pump and solidification of internal contents.
Further, three has been a need for developing a toothpaste composition that solves the problem of sensational displeasure as well as the problem of solidification, while allowing application to a dip pump.
Meanwhile, according to the related art, a liquid toothpaste product having flowability in a plastic container has been launched to improve releasability of toothpaste. However, such a product flows on a toothbrush and has a difficulty in transferring the active ingredients of the toothpaste product to teeth and gum effectively. Moreover, such a liquid toothpaste product may be dried as it is in contact with the air repeatedly, resulting in the problem of an increase in viscosity.
The liquid toothpaste according to the related art causes solidification of internal contents as the viscosity increases, and cannot retain its original form to cause inconvenience of use.
Therefore, active studies have been conducted to prevent solidification of internal contents while maintaining convenience of use of the conventional liquid toothpaste.